81005190 has 32 divisors (see below), whose sum is σ = 222186240. Its totient is φ = 18515424.

The previous prime is 81005179. The next prime is 81005213. The reversal of 81005190 is 9150018.

It is a super-2 number, since 2×81005190² = 13123681613872200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81005190.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 192660 + ... + 193079.

It is an arithmetic number, because the mean of its divisors is an integer number (6943320).

Almost surely, 2^81005190 is an apocalyptic number.

81005190 is an abundant number, since it is smaller than the sum of its proper divisors (141181050).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81005190 is a wasteful number, since it uses less digits than its factorization.

81005190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385756.

The product of its (nonzero) digits is 360, while the sum is 24.

The square root of 81005190 is about 9000.2883287148. The cubic root of 81005190 is about 432.6841119754.

The spelling of 81005190 in words is "eighty-one million, five thousand, one hundred ninety".